4.0-stable review patch. If anyone has any objections, please let me know.
------------------ From: David Hildenbrand <[email protected]> commit b938eacea0b6881f2116a061e6da3ec840e75137 upstream. Commit ea5f49692575 ("KVM: s390: only one external call may be pending at a time") introduced a bug on machines that don't have SIGP interpretation facility installed. The injection of an external call will now always fail with -EBUSY (if none is already pending). This leads to the following symptoms: - An external call will be injected but with the wrong "src cpu id", as this id will not be remembered. - The target vcpu will not be woken up, therefore the guest will hang if it cannot deal with unexpected failures of the SIGP EXTERNAL CALL instruction. - If an external call is already pending, -EBUSY will not be reported. Reviewed-by: Christian Borntraeger <[email protected]> Reviewed-by: Jens Freimann <[email protected]> Signed-off-by: David Hildenbrand <[email protected]> Signed-off-by: Christian Borntraeger <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/s390/kvm/interrupt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -1037,7 +1037,7 @@ static int __inject_extcall(struct kvm_v if (sclp_has_sigpif()) return __inject_extcall_sigpif(vcpu, src_id); - if (!test_and_set_bit(IRQ_PEND_EXT_EXTERNAL, &li->pending_irqs)) + if (test_and_set_bit(IRQ_PEND_EXT_EXTERNAL, &li->pending_irqs)) return -EBUSY; *extcall = irq->u.extcall; atomic_set_mask(CPUSTAT_EXT_INT, li->cpuflags); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
